Separation of metal ions by the influence of a cation-exchange terpolymer involving 2-amino-6-nitrobenzothiazole-ethylenediamine-formaldehyde

A novel terpolymer involving 2-amino-6-nitrobenzothiazole and ethylenediamine with formaldehyde was synthesized by a polycondensation technique using glacial acetic acid as a reaction medium. The resulting chelating terpolymer resin was characterized using elemental analysis, physicochemical parameters, and UV-visible, Fourier transform infrared, 1H NMR and 13C NMR spectral studies. Average molecular weights of the terpolymer were determined using gel permeation chromatography. The surface morphology and the nature of the terpolymer were investigated using scanning electron microscopy and X-ray diffraction. The chelation ion-exchange property of the terpolymer was determined against some common metal ions such as Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Pb2+ using the batch equilibrium method. Effects of parameters such as the pH, contact time and various electrolyte concentrations were studied. The reusability of the terpolymer was checked in terms of its effective repeated usage. The results of the Langmuir and Freundlich adsorption isotherm models were best fitted with each other and the reaction kinetics followed pseudo second-order kinetics. The terpolymer showed good results against Fe3+, Cu2+ and Ni2+ ions compared to those against the other metal ions. © 2014 Society of Chemical Industry